My subject had no trouble assuming a serious pose--other than that he kept wanting to get too close to my seamless paper background:
KlipspringerKlipspringer (Oreotragus oreotragus), or small African antelope, at the Brookfield Zoo in Brookfield, Illinois on September 4, 2014
But, whenever I tried to get him to loosen up, he remained very stiff in front of my camera. This next shot is the best "smile" that I could coax out of him.
KlipspringerKlipspringer (Oreotragus oreotragus), or small African antelope, at the Brookfield Zoo in Brookfield, Illinois on September 4, 2014
Perhaps he's self conscious about his teeth? Or, I suspect it's more my fault than his. It's the photographer's job to make the subject comfortable during a photo shoot.